Ray-filter glass



lie Drawing.

i il'i'fs iii fi oht oilthe human eye, or inter- KR lvliia t tti- Patented .m;. 25, 1927.

My invention relatesto an improxedfilter imiesig e meiimatilyfltaheaseslasu a titer in' a lens 0 tween 9. light'sour'ce as i i ravfefi'iaiiian weanafmea eye; as a globe aroun an el fililfilqel il crjimposing the glass friiilifwliich suchl ulb is made, to ie the. human eye, etth ete'rious effects due to vcertaintraysm the spectrum, ofka wave lengthcommonly hn om as qltra-vieletsand. nfra-crednmyerses the purpose of my invention is to produce a glass which, while cutting ofi th ese invis ble rjiy s, 1gv1 l1 ,0fie.tibcglffiatelf hst sstienoff y a he si lepert nsnf efl en tsem tliaiiordinarx ass hay igg dial usejjaiid afib tiiiiismit such r gy tithe .visibleff oiztionujilon afii nifdrm ratio of lso lifansmission so as some create any distor- 'tion, and to have the light given throu h such filter glass similar and practically t e same as light transmitted through ordlnary clear glass when used for similar pur oses In addition to the utility of this glass in cutting otf the invisible rays because of their ill effect upon the human eye, these invisible raysare also known to be. the principally active or actinio rays of light which cause the fading, disintegration and other chemical effects in. merchandise exposed to light, so that this filter glass is adapted for other uses such as store front windows and show cases and the like. Y

The essence of my invention comprises in incorporating in the batch from which the glass is manufactured a substance herein known as a filter chemical and which will serve in the finished'glass to substantially out 0d the invisible portion of the s ectrum known as the ultra-violet, and partially cut off the infra-red rays, and then introducing some other substance which combined with the filter chemical, will cause the finished product to have the appearance and visibility transmitting power of clearglass for the 1 corresponding commercial use, and yet in no way diminish the efi'ectiveness of the glass upon the actinic rays. r a

A t ical batch from which such glass can be ma e where the finished productis to be used for optical glasses having a final thickness of about 1 millimeters in cross-section is as follows:-.-sand, about 210 lbs; soda ash, about 96 lbs. lim about 37.5 lbs; feldspar, about 10 lbsgso dium nitrate, about 10 ausea and m e, 1525. sci-m 1.11am.

' melted lbs manganese dioxidgaboutilfi 0a.; ferric oxide, about 10 oz.

The glass batch above described may worked up by anIy'Iof the standard glass mak- 1 owever, I preferto bring the glass to'a melt by that process known as recess. In certain cases, however, where t ie ingredients used contain, '1' either one or both. of the chemicals mening processes.

the closed pot tioned; the batch may be brought to a melt and the filter ingredients thereafter added, I that isyany shortage of either the iron oxide I or the .man anese dioxide which may occur in'the raw ,atch, may be made up or an plied subsequently after the batch hasibeen and thereafter thoroughly incorporated. v -Although I haveiveu as my preferred proportions in a hate as above describedlS ;v oz. of manganese dioxide to 10 oz. of ferric oxide which is added to a raw batch of substantially 264 lbs, inthis example the mixi ture of manganese dioxide forms .00256 partsby weight of-the'mixture formin the? i raw batch and the ferric oxide is twot irds of this amount of the man optical glasseshaving a final thiclmess of of substantially .00256 by weight of the mixnese dioxide. It will be observed that t e proportion of .00256 parts by weight ofthe mixiere forms ing the raw batch as above calculated is for meat ture of manganes'e dioxide and 3f;- by weight 1 l' a which is colorless wh n i d f i 1,,

.of this amount of the latter ingredient of ished surfaces and-cuts oil' the ultra-violet. i; light and a portion of the infra-red rays and transmits the visible spectrum un'diminishedr Thus it will be observed that. what I have termed the balanced mixture maybe add e'd'to a glass batch in quantities varyingim; versel with the thickness of the glass in its final mm. It will also be understood that;

I include within the. scope of my invention.

and the claims herein, variations covering a progerties of the other-ingredients used in the etch, which ingredients may be present, dueimpurities; or the proportions may range to take care of the various tinctorial i v V be varied due to the variations and com! i soda glass, borax glass, or any other glas.

' s bining powers which the mixture may have I with the other materials which are used tomake up the glass batch so as to take care of glasses known in the art as" lead glass,

In the claims, by the term balanced mixture I mean tojinclude not only the preferred ratio of manganese dioxide to ferric oxide which I have found gives the actinic light my absorbing qual tiesabove-mentioned, but also mean to include such varia- -tions of manganese dioxide to iron oxide as will take care of the variations of the char acter or composition'ofwthe othermaterials in the batch that are used.

A glass made in accordance with my -111- without appreciably. reducing-the normal .high uniform transmission m the visible parts of the spectrum, such proportions bemg in the case ot lenses, approximately 1% mixture of manganese mentioned in redient of ferric oxide.

2. A'ray filtering glass which. contains] manganese dioxide neutralized by ferric oxidecombined in such'pro ortions that the filter is substantially color es in commercial thicknesses and is capable of absorbin the greater portion of the ultra-violet an infra-red rays without appreciablyredu i ing the normal high uniform transmissionin the yisible parts of the spectrum, Sud-1 1 proportions bein in the case of ophthalmic vention has light ray transmitting properties of the visible spectrum substantially 20 equalto glass having corresponding com-,

as now practiced by the art has ray transmittin property of substantnilly k about 90%.

mercial uses, for instance, an optical lass a li ht 91% of the visib e spectrum.

Optical glass made in accordance with my invention, will have'substantially the same light transmitting properties, namely,

I believe I am the first to produce an apparently colorless ray filter glass capable of absorbing the ultra-violet and infra-red rays, without appreciable diminution of transmission of the rays of light in the visible portion oi the spectrum, and which may be obtained by using common ingredi ents which do not increase the cost of the finished product over that of ordinary com mercial glass for similar commercial uses,

and I'intend to claim the same broadly, This application is filed as a substitute Patent 0 cc File No. 314,751,

Having thus described to invention and for mv a plication filed August 1st, 1919,

". illustrated its use, what I c aim as new and desire tosecure by Letters Patent is:

1. In the art of making glass for the manufacture of ray filters, the method which com rises adding man ane se dioxide and ferric oxide to a batch or making glass in such proportions that the ferric 'oxide'substantially neutralizes the color efiect of the manganese dioxide without impairing its absorbin characteristics for ultra-violet and E infra-re a stantially colorless in commercial thicknesses and is ca able of absorbing the ester 1'- tion oi the ultra-violet and Ely! H rays, whereby the glass is sublenses, 1 mil imeters thick, ..00256 by 3, In a ray filter glass of'any given thick-f e ness, containing a quantity of manganese} dioxide and ferric oxide in such inverse ratio, in the batch from which such lass is made of substantially ,00256 b wei t of the mixture of manganese dioxi e, an' twothirds of this amount of man anese dioxide] by weight of ferric oxide; as t e given thickness of the glass when finished for use bears to 1 millimeters, wherebythe finished article is colorless when viewed from its olished surfaces and cuts 03 the ultra-violet ight, and .a portion of the infra-red ra s, and transmits the visible spectrum I'm minished.

-training-a uantit of manganese dioxide and weight oi manganese dioxide and two-th of this amount y g -,of ferric Pxidu and with varying thicknesses of g a-slwhen ready for. use contains a varying g W. of manganese dioxide and ferric on e m the inverse ratio to such amounts above stated:

as the thickness of such filter glass when ready for use bears to one and-one-hali' n -limeters. v In witness ,whereo-f I havev signed this specification, this 1st Igy of JnlFy, 1925. 

